1. Field of the Invention
The present invention relates to thiazole or imidazole derivatives having an antiulcer activity. This invention also concerns an antiulcer composition efficacious for treating and preventing gastric and duodenal ulcers, which contains them as an effective ingredient.
2. Description of the Related Art
H.sub.2 -receptor antagonists represented by "Cimetidine" and muscarine receptor blockers such as "Pirenzepine" have been used as antiulcer agents. In addition, the development of "Omeprazole" and "NC-1300" based on benzimidazole derivatives that are H.sup.+ /K.sup.+ -ATPase inhibitors possessing new mechanisms is now in the making.
It has been reported that some benzothiazole derivatives possess an inhibitory action on H.sup.+ /K.sup.+ -ATPase ("J. Med. Chem.", 1983, 31, pp. 1778-1785).
We have filed patent applications relating to some relevant techniques (Japanese Patent Application Nos. 293689/1988 and 320468/1988).
Some 2-thio, 2-sulfinyl or 2-sulfonyl-thiazole derivatives have been known with their synthetic processes (e.g. European Patent No. 61425 specification). However, these compounds are described as an antirheumatic agent. Never until now have they been reported to have an antiulcer action.
Some benzothiazole derivatives containing a thiolcarbamoyl group have been known and synthesized by conventional processes so far available in the art (e.g. "J. Heterocycl. Chem.", 24(4), pp. 945-8). This is also true of some benzothiazole derivatives containing an urea group (U.S. Pat. No. 2,410,407). However, these are different from the compounds of this invention represented by Formula (I) ,in terms of the group "B". Never until now have they been reported to possess an antiulcer action.